Problem Description: The extension uses an old version of PHPMailer, which is known to be vulnerable to Remote Code Execution (CVE-2016-10045).

Solution: Versions of this extension that are known to be vulnerable will no longer be available for download from the TYPO3 Extension Repository. The extension author is no longer maintaining this extension. Please uninstall and delete the extension from your installation.

Credits: Credits go to Clemens Riccabona who discovered and reported the vulnerability.